It also remains unclear who hijacked the bus. Local activists said no rebels claimed responsibility, possibly because the kidnappers were criminals seeking ransom or because the move was immediately criticized by opposition groups.

Local rebels threated to storm the Shiite villages, whose residents they say have been armed by the government. But the crisis was resolved early Thursday when the Shiite captives returned home, followed by the release of the Sunni captives later in the day, activists said.

Residents of the Shiite villages could not be reached for comment, though a Facebook page for the larger of the villages, Fua, said in a post Thursday that the captives had returned.

"With God's help we have liberated our kidnapped sisters from hands of the enemies of God," the post said. It also called for "retribution."

Although the abductees have all been freed, the fundamental divide between the Sunni and Shiite villages remains.

"There will have to be a battle in the future because the army is there," said Ismael Khatib, a rebel from the village of Taftanaz, via Skype. "They have tanks there that shell us, so it is natural that the rebels will liberate the area to stop the shelling."

Also Friday, Syrian warplanes and artillery hit targets near Damascus International Airport, a day after at least three car bombings in the city killed more than 80 people, some of them from the security forces, opposition groups said.

Syrian state media said 60 people died in the blasts.

There were no immediate reports of casualties from Friday's shelling, which targeted the towns of Beit Sahm and Shebaa near the main airport road south of the capital, activists said.

On Friday, the Coalition said it would welcome U.S. and Russian mediation to negotiate a peace deal to end the country's civil wall but insisted it would not allow Assad or members of his security services to participate in the talks. The announcement came in a statement posted on the Coalition's Facebook page following two days of meetings in Cairo meant to firm up the group's position on whether to engage in talks.

"Bashar Assad and the security and military leadership responsible for the state of Syria today must step down and be considered outside this political process," the statement said. "They cannot be part of any political solution for Syria and must be held accountable for their crimes."

SNC chief Mouaz al-Khatib has angered some in the opposition by offering to sit down with regime figures to help end the civil war. Friday's announcement appeared aimed at setting the boundaries for any future talks by stressing that Assad and his aides cannot be part of any negotiations.

Also Friday, Reporters Without Borders said a French freelance photographer was seriously wounded a day earlier in Idlib province.

The media watchdog identified the photographer as Olivier Voisin and said he sustained shrapnel wounds to his head and arm. He was taken to a hospital in Antakya, Turkey, for surgery and is in critical but stable condition, the group said.